Here's some good news: If someone steals your credit card and charges hundreds of dollars on it, you're only responsible for $50.
By law, consumers can't be held responsible for more than $50 if they are the victims of credit card fraud and report the theft promptly. So you should contact the card company as soon as you know that a card has been lost or stolen.
In addition, be careful with "pre-approved" offers you receive in the mail. If you toss them out and a dastardly sort picks one up, he can change the address on it to his own and get a card in your name. This is one way that identities are stolen.
It's not a bad idea to buy a paper shredder to destroy credit card offers and documents with confidential information. At office supply stores, you should be able to pick up a modest shredder for around $20 or $30. Identity theft is a massive headache. (Learn more about how to fight or avoid it.)
One last tip: You can make losing your wallet much less painful by periodically photocopying its contents -- including both the front and back of each credit card. That way, if the wallet disappears, you'll know exactly which cards you need to replace, which card companies you need to notify of the loss, and you'll have the contact numbers at hand.
If you or someone you care about is mired in credit card debt, learn how to break free in our Credit Center.